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| United States Patent |
5,277,456
|
|
Mer
, et al.
|
January 11, 1994
|
Adaptor for use with electrofusion fittings
Abstract
An adaptor for use with an electrofusion fitting for enabling a
thermoplastic pipe to be coupled to a dissimilar pipe includes a housing
sleeve for coupling at one end to the dissimilar pipe with the opposite
end being formed on its outer surface with an annular ribbed section
covered by a plastic sleeve. An anchoring ring overlies the annular ribbed
section of the housing sleeve and is effective to firmly anchor the
plastic sleeve to the annular ribbed section of the housing sleeve during
electrofusion of the plastic sleeve to one end of an electrofusion
fitting, and of the plastic pipe to the opposite end of the electrofusion
fitting.
| Inventors:
|
Mer; Zalman (Kfar Saba, IL);
Lever; Ernest (Kibbutz Maagan Michael, IL)
|
| Assignee:
|
Plasson Margan Michael Industries Ltd. (Kibbutz Maagan Michael, IL)
|
| Appl. No.:
|
032035 |
| Filed:
|
March 16, 1993 |
Foreign Application Priority Data
| Current U.S. Class: |
285/21.2; 285/39; 285/148.13 |
| Intern'l Class: |
F16L 013/02 |
| Field of Search: |
285/21,174,175,22
|
References Cited
U.S. Patent Documents
| 4093280 | Jun., 1978 | Yashizawa et al. | 265/174.
|
| 4682797 | Jul., 1967 | Hildner | 285/21.
|
| 4784409 | Nov., 1988 | Piechowiok | 285/21.
|
| 5150922 | Sep., 1992 | Nakashiba et al. | 285/21.
|
| Foreign Patent Documents |
| 2253085 | Oct., 1900 | JP | 285/21.
|
| 675902 | Nov., 1990 | CH | 285/21.
|
Primary Examiner: Arola; Dave W.
Attorney, Agent or Firm: Barish; Benjamin J.
Claims
What is claimed is:
1. An adaptor for use with an electrofusion fitting for enabling a
thermoplastic pipe to be coupled t a dissimilar pipe, comprising: a
housing sleeve formed at one end with coupling means for coupling said
dissimilar pipe thereto, the opposite end of the housing sleeve being
formed on its outer surface with an annular grooved and ribbed section; a
plastic sleeve covering said opposite end of the housing sleeve including
its annular grooved and ribbed section and interlocked therewith to anchor
said plastic sleeve to said housing sleeve, said opposite end of said
housing sleeve extending at least the length of said plastic sleeve and in
contact therewith for the length of said plastic sleeve; and an anchoring
ring overlying said annular grooved and ribbed section of the housing
sleeve and engaging said plastic sleeve and being effective to firmly
anchor the plastic sleeve to the annular grooved and ribbed section of the
housing sleeve during electrofusion of the plastic sleeve to one end of an
electrofusion fitting, and of the plastic pipe to the opposite end of the
electrofusion fitting.
2. The adaptor according to claim 1, wherein said housing sleeve is made of
metal.
3. The adaptor according to claim 1, wherein said housing sleeve is made of
a dissimilar plastic material from said outer plastic sleeve.
4. The adaptor according to claim 1, wherein said housing sleeve is
integrally formed with an outwardly-extending polygonal nut section
adapted to receive a wrench for coupling said dissimilar pipe to the
adaptor.
5. The adaptor according to claim 4, wherein said anchoring ring is of
metal.
6. The adaptor according to claim 4, wherein said anchoring ring is of a
dissimilar plastic material from said outer plastic sleeve.
7. The adaptor according to claim 1, wherein said coupling means on one end
of said housing sleeve includes threads formed on the outer surface of
said housing sleeve.
8. The adaptor according to claim 1, wherein the outer surface of the
housing sleeve on said one end thereof is of conical configuration,
decreasing in diameter towards the outer end thereof.
9. The adaptor according to claim 1, wherein said coupling means includes
threads formed on the inner surface of said housing sleeve.
Description
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to an adaptor for use with an electrofusion
fitting for adapting a plastic pipe to be coupled to a dissimilar pipe.
Electrofusion fittings are now widely used in coupling together two pipes
of plastic material. Such electrofusion fittings include electrical
heating coils which are energized, after the plastic pipes have been
inserted into the opposite ends of the fitting, to bond the two pipes
together via the electrofusion fitting. However, the conventional
electrofusion fitting is not suitable for use where the two pipes to be
coupled together are not both of plastic material, for example where one
pipe is of metal and the other pipe is of thermoplastic material.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide an adaptor for use with an
electrofusion fitting to be bonded to one end of a plastic pipe in order
to enable the thermoplastic pipe to be coupled to a dissimilar pipe, such
as a pipe made of a metal, a thermosetting plastic, or another type of
thermoplastic.
According to the present invention, there is provided an adaptor for use
with an electrofusion fitting for enabling a plastic pipe to be coupled to
a dissimilar pipe, comprising: a housing sleeve formed at one end with
coupling means for coupling the dissimilar pipe thereto, the opposite end
of the housing sleeve being formed on its outer surface with an annular
ribbed section; a plastic sleeve covering the opposite end of the housing
sleeve including its annular ribbed section; and an anchoring ring
overlying the annular ribbed section of the housing sleeve and effective
to firmly anchor the plastic sleeve to the annular ribbed section of the
housing sleeve during electrofusion of the plastic sleeve to one end of an
electrofusion fitting, and of the plastic pipe to the opposite end of the
electrofusion fitting.
For example, the plastic sleeve, and the plastic pipe to which the
dissimilar pipe is to be coupled, may be made of a thermoplastic material
such as polyethylene, polypropylene or polybutylene. However,
thermosetting polymers can also be used, such as cross-linked
polyethylene, so long as the plastic sleeve is bondable to the plastic
pipe.
The housing sleeve and the anchoring ring may be made of metal, such as
stainless steel, brass and mild steel. The components may also be made
from glass or fiber reinforced polymers, such as nylon, acetal resins,
polyvinyl chloride, etc.
As will be described more particularly below, such an adaptor may be bonded
by an electrofusion fitting to one end of a plastic pipe, with the
opposite end available for mechanically coupling another pipe, such as a
pipe made of metal or of a dissimilar plastic.
Further features and advantages of the invention will be apparent from the
description below.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference
to the accompanying drawings, wherein:
FIG. 1 is a longitudinal sectional view illustrating one form of adaptor
constructed in accordance with the present invention;
FIG. 2 is a three-dimensional view illustrating only the housing sleeve in
the adaptor of FIG. 1;
FIG. 3 is a longitudinal sectional view illustrating the adaptor of FIG. 1
bonded by electrofusion to one end of a plastic pipe;
FIG. 4 is a longitudinal sectional view illustrating a second form of
adaptor constructed in accordance with the present invention; and
FIG. 5 is a three-dimensional view illustrating only the housing sleeve in
the adaptor of FIG. 4.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to the embodiment of FIGS. 1-3, the adaptor 2 illustrated in
FIG. 1 is adapted to be bonded, by means of an electrofusion fitting
generally designated 3 in FIG. 3, to one end of a plastic pipe 4, to
enable the plastic pipe to be coupled to a dissimilar pipe, such as a
metal pipe.
The adaptor 2, as more particularly illustrated in FIGS. 1 and 2, comprises
three main elements, namely: a housing sleeve 21, a thermoplastic sleeve
22 on one end of the housing sleeve, and an anchoring ring 23 over one end
of the thermoplastic sleeve 22.
The housing sleeve 21 is integrally formed at an intermediate portion
thereof with an outwardly extending polygonal (hexagonal) nut section 21a
for receiving a wrench. One end of the housing sleeve, on one side of the
polygonal nut section 21a , has an outer surface which is threaded, as
shown at 21b , and is also of conical configuration, decreasing in
diameter towards the outer end of that section. The opposite end 21c of
the housing sleeve 21, on the opposite side of the polygonal nut section
21a , is of uniform diameter for the major portion of its length, but
includes an outer ribbed section, shown at 21d . The latter section
includes an outer face formed with a pair of annular ribs 21e , 21f , and
a plurality of annular grooves 21g for firmly anchoring the outer
thermoplastic sleeve 22 thereto, as will be described more particularly
below.
The outer thermoplastic sleeve 22 encloses the end 21c of the housing
sleeve 21 on the right side of the polygonal nut section 21a . The
thermoplastic sleeve 22 is firmly held between the polygonal nut section
21a of the housing sleeve 21, and the ribbed end section 21d of the
housing sleeve.
Anchoring ring 23 is applied over the ribbed end section 21d of the housing
sleeve 21. As described more particularly below, ring 23 serves to firmly
anchor the thermoplastic sleeve 22 to the housing sleeve 21 during the
bonding of the adaptor 2 to the electrofusion fitting 3.
The electrofusion fitting 3, as shown in FIG. 3, includes a thermoplastic
sleeve 31. A first electrical heating coil 33 is embedded adjacent the
inner surface of fitting 3 on one side of its inner rib 32, and a second
electrical heating coil 34 is embedded on the inner surface of the fitting
at the opposite side of its rib 32. The two electrical heating coils 33
and 34 are electrically connected and may be energized simultaneously via
externally-exposed electrical terminals 33a and 34a , respectively.
Adaptor 2 may be inserted into on side of the electrofusion fitting 3, and
the thermoplastic pipe 4 may be inserted into the opposite side of fitting
3. The two electrical heating coils 33, 34 may then be energized via their
electrical terminals 33a , 34a . The heat generated by the heating coil 33
softens the inner surface of the thermoplastic sleeve 31 of the
electrofusion fitting 3 and also the outer surface of the thermoplastic
sleeve 22 of the adaptor 2, thereby producing a strong bond or weld
between the two surfaces when they cool. Anchoring ring 23 prevents any
radially-outward expansion of the respective end of the thermoplastic
sleeve 22, thereby forcing the plastic sleeve to firmly bond to the ribs
21e , 21f and grooves 21g of the ribbed section 21d of the housing sleeve
21.
The heat generated by the heating coil 34 softens the inner surface of the
electrofusion fitting 31 and also the outer surface of the thermoplastic
pipe 4, thereby producing a strong bond or weld between the two when they
cool.
The thermoplastic pipe 4, with the adaptor 2 welded to one end by the
electrofusion fitting 3, may thus be coupled to a dissimilar pipe, such as
a metal pipe, via the external threads 21b at the end of the adaptor.
It will be appreciated that the adaptor 2 can be selected according to the
dissimilar pipe to be coupled to the plastic pipe 4. FIGS. 4 and 5
illustrate another adaptor construction which can be used for this
purpose.
Thus, the adaptor illustrated in FIGS. 4 and 5, and therein generally
designated 5, also includes a housing sleeve 51 formed with an
outwardly-extending polygonal nut section 51a for receiving a wrench. One
end of the housing sleeve 51 is covered by an outer thermoplastic sleeve
52 electrofusion fitting, such as fitting 3 illustrated in FIGS. 1-3. The
opposite end of the electrofusion fitting is to be bonded to the plastic
pipe, e.g., pipe 4 in FIG. 3.
In the adaptor construction illustrated in FIGS. 4 and 5, the end of the
adaptor to be coupled to the dissimilar pipe (e.g., a metal pipe) is
formed with internal threads 51b for this purpose. The remainder of the
adaptor 5 illustrated in FIGS. 4 and 5 is otherwise of the same
construction as described above with respect to FIGS. 1-3, including the
uniform diameter section 51c and the outer ribbed section 51d on the
housing sleeve, the outer plastic sleeve 52, and the anchoring ring 53.
It will thus be seen that when an adaptor, such as illustrated in FIGS. 4
and 5, is welded by the electrofusion fitting to one end of a plastic
pipe, the plastic pipe is thus enabled to be coupled to another dissimilar
pipe, such as one of metal, via the internal threads 51b of the adaptor.
The adaptor can be of other constructions, to enable coupling the
respective end of the plastic pipe 4 to a dissimilar pipe by other means,
such as by welding, brazing or adhesives. It will also be appreciated that
the adaptor can be joined to other types of plastic pipes, such as elbows,
tees, and the like.
Many other variations, modifications and applications of the invention will
be apparent.
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